Method and apparatus for attaching pipelines to offshore structures

ABSTRACT

A pipe guidance system is attached to an offshore structure. A remote pipe guide connected to a pipeline being laid underwater is pulled to and properly positioned adjacent the offshore structure by means of the pipe guidance system. A riser pipe is guided to a position for connection to the pipeline by means of a riser guide which is also attached to the offshore structure. Then the pipeline and riser pipe are connected together. The pipe guidance system includes at least one pulley connected to the offshore structure and a cable arranged about the pulley. One end of the cable is connected to power means for applying a pulling force on the cable and the other end is connected to the pipe guide.

Pattison et al.

[451 Sept. 12, 1972 [54] METHOD AND APPARATUS FOR ATTACHING PIPELINES TOOFF- SHORE STRUCTURES Inventors: Martin Oren Pattison, Los Angeles,Calif; Willy Frank Bohlmann, Jr., Los Angeles, Calif.

Assignee: Esso Production Research Filed: Feb. 10, 1971 Appl. No.:114,286

US. Cl ..61/72.3 166/.6 Int. Cl ..Fl6l l/00 Field of Search ..61/72.3,72.1, 46.5; 166/.5,

References Cited UNITED STATES PATENTS LAY BARGE SEA TLOOR Hindmam...6l/72.3 Gardner, Jr. ..6l/72.3

[57 ABSTRACT A pipe guidance system is attached to an offshorestructure. A remote pipe guide connected to a pipeline being laidunderwater is pulled to and properly positioned adjacent the offshorestructure by means of the pipe guidance system. A riser pipe is guidedto a position for connection to the pipeline by means of a riser guidewhich is also attached to the offshore structure. Then the pipeline andriser pipe are connected together. The pipe guidance system includes atleast one pulley connected to the offshore structure and a cablearranged about the pulley. One end of the cable is connected to powermeans for applying a pulling force on the cable and the other end isconnected to the pipe guide.

9 Claims, 8 Drawing Figures I6 STRUCTURAL GUIDE .PATENTED SEP 12 m2 sum2 or 2 STRUCTURAL sums LATCH RISER GUIDE MARTIN O. PATTISON,

WILLY F. BOHLMANN JR.,

1 N VENTORS.

A TTORNEY.

METHOD. AND APPARATUS FOR ATTACHING PIPELINE TO OFFSHORE STRUCTURESBACKGROUND OF THE INVENTION the pipeline to an offshore structure andthen connecting the pipeline to a riser pipe which is arranged on theoffshore structure.

SUMMARY OF THE INVENTION The present invention involves a method forlaying offshore pipelines and connecting these pipelines to offshorestructures and briefly comprises the steps of: laying a pipeline havinga curved section of pipe on the free end thereof on water bottom undertension from a lay barge; pulling the submerged free end of saidpipeline to an offshore structure; lowering a riser pipe from the waterssurface to said free end of said pipeline; and then connecting saidriser pipe to said free end of said pipeline.

The present invention also involves offshore structure apparatuscomprising an offshore platform having a riser pipe guide arrangedthereon; a structural guide connected to said offshore platform adjacentthe lower end of said riser pipe guide; a riser pipe extending throughsaid riser pipe guide; a submerged pipeline; a pipe guide having acurved section of pipe arranged thereon, one end of said curved sectionof pipe being connected at one end to said pipeline and at the other endto said riser pipe; pulley means connected to said offshore platform; acable connected at one end to said pipe guide and passing through saidpulley; power means connected to the other end of said cable forexerting a pulling force on said cable to pull said pipe guide andpipeline connected thereto to said offshore platform.

BRIEF DESCRIPTION OF THE DRAWINGS trated in FIGS. 1 and 2 in greaterdetail;

FIG. 6 is a view taken along lines 66 of FIG.

FIG. 7 illustrates another embodiment of the invention; and v FIG. 8illustrates still another embodiment of themvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION There is shownin FIGS. 1 and 2 an offshore platform structure 10 located in a body ofwater 11. Platform 10 is provided with an upper deck 12 and a lower deck13. A crane I4 is positioned on deck 12 and a winch 15 is positioned ondeck 13. A structural guide 16 is connected to offshore structure 10 onsea floor or water bottom 17. A riser pipe guide 18 is also attached tooffshore structure 10. A pulley 21 is connected to the offshorestructure 10 adjacent the lower portion thereof. A cable 25, connectedat one end to winch 15, extends about pulley 21 and through structuralguide 16 to a pipe guide 26 as shown in FIG. 1. A pipeline 27 is shownbeing laid on water bottom from a lay barge 28 being towed by a tug 29.

, Details of the structural guide 16 and pipe guide 26 are shown inFIGS. 3 and 4. Structural guide 16 is a box like frame of weldedconstruction which is attached to platform leg 30 and horizontal crossmember 32 or to horizontal cross member 32 only. End plate member 34 isprovided with an opening 35 through. which cable 25 extends. Springbiased latch members 37 are mounted in each side 36 of structural guide16. Sides 36 are also tapered to accommodate the forward sides 40 of acarriage or sled 41 of pipe guide 26. Cable 25 is connected to theforward end member of sled 41 as at 42. The trailing edges of sides 40form shoulders 43 which are engaged by latches 37 when guide 26 ispositioned in structural guide 16. A curved section of pipe 50 isconnected to the free end of pipeline 27 and secured to sled 41 byclamps 51 and support 52. The curved section of pipe 50 terminates in aconnector portion 53.

Riser pipe guide 18 (FIG. 5) is secured to cross bracing 61 of offshorestructure 10 by clamps or welded bracket 62. The riser pipe guideincludes a T-shaped member 63 (see FIG. 6) on which guide elements 64,secured to riser pipe 28 by clamps 46, slide. The lower end of riserpipe 28 is provided with a hydraulically operated connector 65. Ahydraulic hose 66 extends from connector 65 to decks 12 or 13. Thehydraulic connector 65 is commercially available and may be suitably onesuch as disclosed in the Composite Catalog of Oil Field Equipment andServices, page 1248, Vol. 1, 1966-67, Published by World Oil.

In the operation of this apparatus the free endof cable 25 shown indashed lines in FIG. 1 is connected to pipe guide 26 initially locatedon lay barge 28 and the first section of pipeline 27 is connected to thecurved section of pipe 50 secured to sled 41. Pipe lay barge 28 beginslaying pipeline 27 under tension while winch 15 on deck 13 takes in onthe pipe guide 26 until pipe guide 26 is pulled into the structure guide16 as additional sections of pipeline 27 are laid. Latches 37 securelylock pipe guide 26 to structure guide 16. Horizontal movement of pipeguide 26 when contained in structure guide 16 is restricted but verticalmovement although restrained is not fixed. After securing the pipe guidein the structure guide, pipe lay barge 28 continues laying the pipelineon the water bottom.

Pipeline riser 28, together with connector 65 and hydraulic hose 66 andguide members 64, is guided by riser pipe guide 63 along a predeterminedpath to the water bottom. The riser pipe is made up as it is lowered bywelding additional joints or by other means of attachment. When it is inposition adjacent the end 53 of curved pipe 50 connector 65 is operatedto connect riser pipe 28 and curved pipe 50 together.

A buoyant tower platform structure 10A is illustrated in FIG. 7. A ball(or swivel joint) 70 connects platform 10A to a base member 71 securedto the sea floor 17. Platform 10A contains buoyancy means and decks 12and 13. A winch 15 is positioned on deck 13. Base member 71 is providedwith a pulley 21. As in the embodiment of FIGS. 1 and 2 a cable 25 isconnected at one end to winch and extends about pulley 21 and throughstructural guide 16 to pipe guide 26. A modified riser pipe 28A containsa flexible pipe section 29 on its lower end to permit the riser pipe toflex when the platform oscillates on the joint. The pipeline is laid andconnected to the riser pipe in the same manner as described heretoforewith respect to FIGS. 1 and 2.

In FIG. 8 a submerged platform 108 provided with a riser pipe guide 18Bisshown. In this modification a cable pulley is attached to a supportpost or piling 19 which is driven into the sea] floor 17 adjacentplatform 10B. Winch 15, which, as in the other embodiments is used toapply pulling force to cable 25, is located on a floating vessel 80. Thepipe guide system of FIG. 8 operates the same way the guide systems ofFIGS. l-2 and FIG. 7 operate.

Advantages of the method and apparatus of this invention include thefollowing:

It is not necessary to moor the pipe lay barge close to the offshorestructure. The apparatus provides its own alignment. Pipe layingoperations can be continuous once the pipe guide is attached to theoffshore structure. The invention is applicable to various types ofoffshore structures including a rigid type platform, a submerged rigidtype platform and a buoyant tower oscillation type platform. It is notnecessary for a pipe lay barge to install the riser. Pipe layingoperations can be initiated at a considerable distance from thestructure.

Having fully described the operation, advantages, method and apparatusof my invention, I claim:

1. A method for laying pipelines and connecting said pipelines to anoffshore structure arranged in a body of water and extending from thebottom of said water to above the surface of said water comprising;

securing a curved section of pipe to a pipe guide capable of beingpulled along the bottom of said water, said curved section of pipehaving one end extending generally horizontally and the other endextending generally vertically when said pipe guide is positioned on thebottom of said water;

connecting one end of a pipeline being laid to said offshore structureto said one end of said curved section of pipe;

pulling said pipe guide and curved section of pipe and said pipelineattached to said curved section of pipe along the bottom of said waterand guiding said pipe guide into a structure guide attached to saidoffshore structure adjacent the bottom of said water and then lockingsaid pipe guide in said structure guide;

lowering a riser pipe from the surface of said water to adjacent thebottom of said water guided by a riser guide attached to said offshorestructure and extending substantially vertically from adjacent thesurface of said water to adjacent the bottom of said water; and

then connecting said riser pipe to the other end of said curved sectionof pipe.

2. A method as recited in claim 1 in which said pipeline is connected tosaid curved section of pipe at the surface of said water and said pipeguide and pipeline is pulled along the bottom of said water into saidstructure guide by means of a cable attached at one end to said pipeguide and at the other end to pulling means positioned on said offshorestructure,

said one end of said cable being attached to said pipe guide at thesurface of said water.

3. A method as recited in claim 2 in which said riser pipe is connectedto the other end of said curved pipe by remotely operated hydraulicmeans. 5. Apparatus for laying a pipeline and connecting said pipelineto an offshore structure arranged in a body of water and extendingupwardly from the bottom of said water comprising:

a riser pipe guide attached to said offshore structure and extendingsubstantially vertically;

a structural guide connected to said offshore structure adjacent thelower end of said riser pipe guide;

a pipe guide capable of being pulled along the bottom of said water intosaid structural guide;

a curved section of pipe secured to said pipe guide,

said curved section of pipe having one end extending substantiallyhorizontally and the other end extending substantially vertically whensaid pipe guide is arranged on the bottom of said water;

a submerged pipeline connected. to said one end of said curved sectionof pipe;

a riser pipe arranged on said riser pipe guide having one end extendingto adjacent the upper end of said offshore structure and the other endthereof connected to the other end of said curved section of pipe;

pulling means including power means located on said offshore structureand a cable connected to said pipe guide, said power means being capableof pulling said pipe guide and curved section of pipe and said pipelineconnected thereto into said structural guide;

said structural guide comprising a box-like frame having side platemembers and an end plate member, said end plate member having an openingthrough which said cable extends; and

spring biased latches arranged on said side plate members adapted toengage said' pipe guide.

5. Apparatus as recited in claim 3 in which said pipe guide comprises asled having side members and an end member, said cable being connectedto said end member; and said side members having openings thereinadapted to engage said structural guide.

6. Apparatus for laying a pipeline and connecting said pipeline to anoffshore structure arranged in a body of water and extending upwardlyfrom the bottom of said water comprising:

a riser pipe guide attached to said offshore structure and extendingsubstantially vertically;

a structural guide connected to said offshore structure adjacent thelower end of said riser pipe guide;

a pipe guide capable of being pulled along the bottom of said water intosaid structural guide;

a curved section of pipe secured to said pipe guide,

said curved section of pipe having one end extending substantiallyhorizontally and the other end extending substantially vertically whensaid pipe guide is arranged on the bottom of said water;

a submerged pipeline connected to said one end of said curved section ofpipe;

a riser pipe arranged on said riser pipe guide having one end extendingto adjacent the upper end of said offshore structure and the other endthereof connected to the other end of said curved section of pipe;

pulling means including power means located on said offshore structureand a cable connected to said pipe guide, said power means being capableof pulling said pipe guide and curved section of pipe and said pipelineconnected thereto into said structural guide; I

said pipe guide comprising a sled having side members and an end member,said cable being connected to said end member; and said side membershaving openings therein adapted to engage said structural guide.

7. Apparatus for laying a pipeline and connecting said pipeline to anoffshore structure arranged in a body of water and extending from thebottom of said water to above the surface of said water comprising:

a riser pipe guide attached to said offshore structure and extendingsubstantially vertically from adjacent the surface of said water toadjacent the bottom of said water;

a structural guide connected to said offshore structure adjacent thelower end of said riser pipe guide;

a pipe guide capable of being pulled along the bot tom of said waterinto said structural guide;

a curved section of pipe secured to said pipe guide,

said curved section of pipe having one end extending substantiallyhorizontally and the other end extending substantially vertically whensaid pipe guide is arranged on the bottom of said water;

a submerged pipeline connected to said one end of said curved section ofpipe;

a riser pipe arranged on said riser pipe guide having one end extendingabove the surface of said water and the other end thereof connected tothe other end of said curved section of pipe; and

pulling means including power means located on said offshore structureand a cable connected to said pipe guide, said power means being capableof pulling said pipe guide and curved section of pipe and said pipelineconnected thereto to said 'structural guide.

8. Apparatus as recited in claim 6 in which at least the lower end ofsaid riser pipe is flexible.

1. A method for laying pipelines and connecting said pipelines to anoffshore structure arranged in a body of water and extending from thebottom of said water to above the surface of said water comprising;securing a curved section of pipe to a pipe guide capable of beingpulled along the bottom of said water, said curved section of pipehaving one end extending generally horizontally and the other endextending generally vertically when said pipe guide is positioned on thebottom of said water; connecting one end of a pipeline being laid tosaid offshore structure to said one end of said curved section of pipe;pulling said pipe guide and curved section of pipe and said pipelineattached to said curved section of pipe along the bottom of said waterand guiding said pipe guide into a structure guide attached to saidoffshore structure adjacent the bottom of said water and then lockingsaid pipe guide in said structure guide; lowering a riser pipe from thesurface of said water to adjacent the bottom of said water guided by ariser guide attached to said offshore structure and extendingsubstantially vertically from adjacent the surface of said water toadjacent the bottom of said water; and then connecting said riser pipeto the other end of said curved section of pipe.
 2. A method as recitedin claim 1 in which said pipeline is connected to said curved section ofpipe at the surface of said water and said pipe guide and pipeline ispulled along the bottom of said water into said structure guide by meansof a cable attached at one end to said pipe guide and at the other endto pulling means positioned on said offshore structure, said one end ofsaid cable being attached to said pipe guide at the surface of saidwater.
 3. Apparatus for laying a pipeline and connecting said pipelineto an offshore structure arranged in a body of water and extendingupwardly from the bottom of said water comprising: a riser pipe guideattached to said offshore structure and extending substantiallyvertically; a structural guide connected to said offshore structureadjacent the lower end of said riser pipe guide; a pipe guide capable ofbeing pulled along the bottom of said water into said structural guide;a curved section of pipe secured to said pipe guide, said curved sectionof pipe having one end extending substantially horizontally and theother end extending substantially vertically when said pipe guide isarranged on the bottom of said water; a submerged pipeline connected tosaid one end of said curved section of pipe; a riser pipe arranged onsaid riser pipe guide having one end extending to adjacent the upper endof said offshore structure and the other end thereof connected to theother end of said curved section of pipe; pulling means including powermeans located on said offshore structure and a cable connected to saidpipe guide, said power means being capable of pulling said pipe guideand curved section of pipe and said pipeline connected thereto into saidstructural guide; said structural guide comprising a box-like framehaving side plate members and an end plate member, said end plate memberhaving an opening through which said cable extends; and spring biasedlatches arranged on said side plate members adapted to engage said pipeguide.
 4. Apparatus as recited in claim 3 in which said pipe guidecomprises a sled having side members and an end member, said cable beingconnected to said end member; and said side members having openingstherein adapted to engage said structural guide.
 5. Apparatus for layinga pipeline and connecting said pipeline to an offshore structurearranged in a body of water and extending upwardly from the bottom ofsaid water comprising: a riser pipe guide attached to said offshorestructure and extending substantially vertically; a structural guideconnected to said offshore structure adjacent the lower end of saidriser pipe guide; a pipe guide capable of being pulled along the bottomof said water into said structural guide; a curved section of pipesecured to said pipe guide, said curved section of pipe having one endextending substantially horizontally and the other end extendingsubstantially vertically when said pipe guide is arranged on the bottomof said water; a submerged pipeline connected to said one end of saidcurved section of pipe; a riser pipe arranged on said riser pipe guidehaving one end extending to adjacent the upper end of said offshorestructure and the other end thereof connected to the other end of saidcurved section of pipe; pulling means including power means located onsaid offshore structure and a cable connected to said pipe guide, saidpower means being capable of pulling said pipe guide and curved sectionof pipe and said pipeline connected thereto into said structural guide;said pipe guide comprising a sled having side members and an end member,said cable being connected to said end member; and said side membershaving openings therein adapted to engage said structural guide. 6.Apparatus for laying a pipeline and connecting said pipeline to anoffshore structure arranged in a body of water and extending from thebottom of said water to above the surface of said water comprising: ariser pipe guide attached to said offshore structure and extendingsubstantially vertically from adjacent the surface of said water toadjacent the bottom of said water; a structural guide connected to saidoffshore structure adjacent the lower end of said riser pipe guide; apipe guide capable of being pulled along the bottom of said water intosaid structural guide; a curved section of pipe secured to said pipeguide, said curved section of pipe having one end extendingsubstantially horizontally and the other end extending substantiallyvertically when said pipe guide is arranged on the bottom of said water;a submerged pipeline connected to said one end of said curved section ofpipe; a riser pipe arranged on said riser pipe guide having one endextending above the surface of said water and the other end thereofconnected to the other end of said curved section of pipe; and pullingmeans including power means located on said offshore structure and acable connected to said pipe guide, said power means being capable ofpulling said pipe guide and curved section of pipe and said pipelineconnected thereto to said structural guide.
 7. Apparatus as recited inclaim 6 in which at least the lower end of said riser pipe is flexible.8. Apparatus as recited in claim 6 in which said offshore structure is apivotally based buoyant tower capable of oscillation.